Hydrocarbon oil treatment



March 22, 1938. s. w. FERRIS i 2,111,968

HYDROCARBON OIL TREATMENT Filed March 30, 1935 Volume of Un inve-nfor-Seymozzr Wfrrzls' In accordance with my invention, hydrocarbon ate thesetwo extremes.

30 chain and/or ring structures in which the hydrothe generalrelationship expressed by the for- 30 gen to carbon ratio is less thanin the foregoing mulaeseries. A large number of individual compounds ofeach series and of differing boiling points are G=1 -0 72 10g(v. 38)

35 present in petroleum. V, 35

The various types of crude petroleum, which or G:'24+0755a+0'0221g("35'5) are generally classified into three groups, namely, paraflinicbase, naphthenic or asphaltic base, in which G is the specc gravity at60 F., and mixed base, contain the various series of hy- V and V' arerespectively Saybolt universal 40 drocarbcns mentioned heretofore indifferent viscositi'es at 100 F. and 210 F., and a is a 40 UNITED STATESPATENT OFFICE mmnocAnBoN on. TREATMENT Seymour W. Ferris, Aldan, Pa.,assignor to The Atlantic Refining Company,`Philadelphia, Pa., acorporation of Pennsylvania Application March so, 193s, serial No.663,586

'31 claims. (c1. 19e- 13) y This Ainvention relates to the art ofhydrocaras in the naphthenic or 'asphaltic base crude oils, bon oilrefining and has particular reference to there is a relatively largeproportion cf hydrothe separation of hydrocarbon oils, especiallycarbons having ring structures and a low hydrocrude petroleum orpetroleum products, into gen to carbon ratio. Mixed base crude oils,such 5 "fractions of different chemical composition while as areobtained from the Mid-Continent oil fields, 5

of approximately lthe same distillation range. contain hydrocarbons inproportions intermedioils, particularly oils of substantial viscosity,are 'Ihe variance in the proportion of the different separated intovarious fractions by means of series of hydrocarbons in paraftinic,naphthenic,

fractional extraction with a halogenated aroand mixed base oils isevidenced by the physical 10 matic compound or a mixture of solventscon'- properties of the various oils and particularly by tainingsubstantial amounts of such aompound. the relationship of the specificgravity to the By the term halOgenated aromatic compound I viscosity ofone oil as compared with another. mean to include one or amixture of twoor more For example, an oil derived vfrom a Pennsylvania llipolysubstituted benzenes containing as substitcrude and having aviscosity of 400 seconds SayllenGS at least One halOgen and preferablyat bolt universal at 100 F., will show a specific least one substituentother than halogen or alkyl, gravity at 60 F. of about 0.878, whereas an011 Such as, fOr example, -OH, N02, NH2, of corresponding viscosityproduced fromanaph- -CHQ -NHCH3. Examples of this `class of theniccrude, such as one from the Gulf Coast 2o compounds are Chlor-phenol,chlor-nitrobenzene area, will show a specific gravity of about 0.933 20and chlor-aniline. f at 60 F. The relationship between the viscosity Itis recognized in the art that mineral oils, and` gravity indicates thedegree of paraffinlcity Such aS Petroleum. comprises essentially a mixornaphthenicity of the oil, and such relationship ture of hydrocarbons ofvarious groups or homolmay be expressed by the viscosity-gravity convogous series of compounds, such for example, as etant as hereinafterdescribed, 25

gparains of the general formula CuHzni-z, olefins If a given lcrudepetroleum be distilled into of the general formula CnHz'n,hydroaromatics successive fractions and the speciflc gravities and andpolymethylenes of the same empirical forviscosities of the severalviscous fractions be mula, and -various other series of compounds ofdetermined, it will be found that they conform to proportions. Forexample, in the paraffin base constant known as the viscosity-gravityconstant. crude oils, such as those obtained from the oil Viscousfractions from each of the different -felds of Pennsylvania, there is arelatively large types of crude have different viscosity-gravityproportion of hydrocarbons having a chain strucconstants. While, ingeneral, viscous fractionsture and a high hydrogen to carbon ratio,wherefrom a single crude have substantially the same 45viscosity-gravity constant, such constant is lower for fractions of theparafnic crudes than is the constant for fractions of thenaphtheniccrudes. An article entitled The viscosity-gravity constant ofpetroleum lubricating oils byJ'. B. Hill and H. B. Coats, which will befound in vol. 20, page 641 et seq., Ind. and Eng. Chem. for' June 1928,explains the determination of such constant for several typical oils.

The viscosity-gravity constant is, therefore, an index of theparailinicity or naphthenicity of viscous oils, since when a given crudeis distilled, the fractions thereof collected, and the specific gravityand the viscosity of each of the viscous fractions determined, suchspecic gravities and viscosities substituted in the formula, and theviscosity-gravity constants of the fractions calculated, it will befound that such constants are substantially the same.

The viscosity-gravity constants of the viscous fractions of some of thetypical crudes are as follows:

Milltown (Pennsylvaniai- 0.8067 Burbank (Mid-Continent) 0.8367 Guadalupe(Gulf COaSt) 0.8635 Mirando (Gulf Coast) 0.9025

While the above figures indicate the viscositygravity constants ofspecific oils from several types of crudes, it is to be understood thatfor any particular type of crude such constant may be within a rangebetween values above and below the constant of the typical crude given.For example, viscous oils resulting from the distillation ofMid-Continent crudes have viscositygravity constants ranging from about0.835 to about 0.855, whereas the viscous fractions resulting fromdistillation of Pennsylvania type crudes range from about 0.805 to0.828, and in most instances, are below 0.820. Oils are increasinglyparaiiinic as their viscosity-gravity constants decrease.

My invention is based upon the discovery that oils containing both theparafnic and the naphthenic series of hydrocarbons may be fractionaliyextracted with a halogenated aromatic compound and more particularlywith a chloro-aromatic compound. The various series of hydrocarbonspossess a differential solubility in such a solvent, the napthenichydrocarbons being more soluble therein than the parafnic hydrocarbons.IBy means of extraction with such solvent, it is therefore possible toeffect a partial separation of the naphthenic hydrocarbons from theparanic, and to obtain from an oil containing both classes ofhydrocarbons, an oil .fraction which is more paranic than the originaloil and one which is more naphthenic. By my invention, for example, itis possible to produce an oil of the quality normally obtained fromAppalachian crudes, from crudes of the mixed base type from theMid-Continent area, and conversely, to obtain oils from mixed basecrudes such as are normally obtained from the naphthenic oils of theGulf Coast area. In general, from oils from any source there may beobtained by my process, oils which are respectively more parafnic andnaphthenic than the oils normally obtained from such source bydistillation.

In accordance with my invention I rst mix the v oil to be treated with asuitable proportion of the solvent at a temperature such that completesolution is effected and a homogeneous liquid obtained. I then cool themixture to a temperature at which separation of the liquid into atwo-layer system will take place. The upper layer will contain a.relatively small amount of solvent dissolved in the paranic portion ofthe oil while the lower layer will contain the morenaphthenic oildissolved in the solvent. Or, I may agitate the mixture of solventandoil at temperatures at which the liquids are only partially miscible,and thereby effect solution of the naphthenic portion of the oil in thesolvent. In either of theI above procedures I may take advantage of theprinciples of countercurrent extraction. After extraction, I effectseparation of the two layers which form, by any suitable procedure, asfor example, by decantation. I thenr remove from eachv of the separatedlayers, the portion of the solvent which each contains, by suitableprocedure, such as by vacuum distillation, thereby to obtain two oils ofsimilar distillation range but of dierent chemical composition anddiierent physical properties. Before removing the solvent from the upperand more param-nic layer, I may add a further quantity of solvent andrepeat the extraction, thereby to remove additional naphthenicvconstituents from said layer.

My invention may be illustrated by the following specic example:

parts of an untreated distillate obtained from a Mid-Continent crude oiland having a viscosity of 154 seconds Saybolt universal at 210 F., aspecic gravity at 60 F. of 0.9176, and a viscosity-gravity constant of0.836 was mixed with 300 parts of o-chlor-phenol and heated to.mi

slightly above the temperature of complete miscibility, i. e., toapproximately 27 C. 'I'he homogeneous liquid which resulted was cooled,with agitation, to 5 C. and allowed to settle, whereupon a two layersystem formed which consisted of an upper undissolved oil layercomprising 86.4 parts ofthe mixture and a lower layer of oil dissolvedin o-chlor-phenol comprising 313.6 parts of the mixture.` Afterseparation the layerswere each freed of the solvent by vacuumdistillation. 'I'he undissolved fraction yielded 20.5 parts ofo-chlor-phenol and 65.9 parts of an oil having a viscosity of 128seconds Saybolt universal at 210 F., a specific gravity of 0.8967 and aviscosity-gravity constant of 0.812. 'Ihe dissolved fraction yielded279.5 parts of o-chlor-phenol and 34.1 parts of oil having a viscosityof 191 seconds Saybolt universal at 210 F., a specific gravity of 0.9471and a viscosity-gravity constant of 0.872.

From the above example it will be seen that by my process it is possibleto obtain from a typical mixed base stock, two fractions, one having thecharacteristics of a Pennsylvania oil and the other the characteristicsof a Gulf Coast oil.

Table I, given below, is a summary of extraction data comparing a groupof substituted benzene solvents with their corresponding halogenderivatives, the chlor-compounds. The data in each case represents asingle extraction with the solvent indicated therein. It will beobserved that each non-halogenated solvent was employed in theproduction of two undissolved oil fractions of differentviscosity-gravity constants, by using two different ratios of volume ofsolvent to volume of oil stock treated. Two extractions with the halogenderivative of each solvent were also made on the same oil stock as abasis for comparison of the halogenated and non-halogenated solvents.

tity of oil of a given viscosity-gravity constant with the employment ofthe least amount of sol- Table I Vol. ol undis- Ratio vol. Vis-grav.

Vis-grav. Vlsfgrav solved oil Solvent ssollegt efetcl colstzntkol ucggggconsltan oil pro?. per i201.

' o soc ssove o1 o soven stock oil product employed Phenol 1. 072 1 o.sae o. 826 o. ssc o. 825

O-Chlor-phenol 1. 241 l 0. S36 0. 825 0. S85 0. 825

Ph en nl 3 0. 836 0. 815 0. 871 0. 206

Ochlorphenol 3 0. 836 0. 812 0. 872 0. 220

Aniline 1. 022 1 0. 874 0. 854 O. 939 0. 754

O -chloraniline l. 213 1 0. 874 0. 842 (l. 909 0. 518

Aniline 3 0. B74 0. 835 0. 927 0.178

-chlorani1ine 3 0. 874 0. 823 0. 924 0. 153

Bcnzaldehyde 1.050 1 0. 808 0. 802 0. 839 0. 825

Ochlorbenzaldehyde 1 0. 808 0. 802 0. B39 0. 825

Benzaldehyde 3 0. 808 0. 796 0: 201

O-chlor-beuzaldehyde. 3 0. 808 0. 794 O. 832 0. 192

N itrobenzene., 1. 203 l 0. B08 0. 801 0. 845 0. 837

O-chlor-nitrobenze 1. 368 l 0. 808 0. 800 0.854 0. 840

Ntrobenzone 3 0. 808 0. 795 0. 833 0. 207 O-chlonnitrobenzene 3 0. 8080. 792 0.838 0. 20B I The above table shows that halogenation increasesthe specic gravity of the aromatic solvents very substantially, whichfact is important in that the specic gravity differential betweensolvent and oil is increased, thereby causing an increased rate ofseparation of the oil and solvent layers, which factor is of importancein the economic operation of the extraction process. Itis desirable tohave the specic gravity of the selective solvent as widely differentfrom the specific -gravity of the oil as possible, in order to bringabout a rapid separation of the layers, particularly when a continuousprocess of extraction is employed. The halogen derivatives ofsubstituted benzene hydrocarbons have, in general, a higher specificgravity than the corresponding non-halogenated solvents, and, as aclass, are capable of producing, in a single extraction, a dissolved andan undissolved oil fraction having a greater viscosity-gravity constantdifferential than the non-halogenated solvents are capable of producing.l

While the superiority of the halogenated solvents over the correspondingnon-halogenated compounds is indicated by the -above table, suchsuperiority is more clearly shown by the graphs of the accompanyingdrawing, said drawing comprising four graphs each containing two curvesdrawn from data presented in Table I. In each graph, viscosity-gravityconstant of undissolved oil is plotted as abscissa against the ratio,volume of undissolved oil per volume of solvent, as ordinate. One curveindicates the results obtained by a single batch extraction of the oilstock with a non-halogenated selective solvent and the other vent, itfollows that the curve having the ilattest slope and lying nearest thetop of the graph indicates the most desirable selective solvent. Thecurve which lies farther to the left and above the other curve indicatesa greater volume of undissolved oil of given viscosity-gravity constantper volume of solvent employed in the production thereof, than does .theother curve, thereby showing the superiority of one solvent over theother. Or, from another point of view, for a constant ratio of volume ofundissolved oil to volume of solvent, the rst mentioned curve shows theundissolved oil to be of a lower viscositygravity constant than thatindicated by the other curve. This comparison of selective solvents, asmade in each graph of the accompanying drawing, is developed at lengthin an article entitled Solvent extraction of lubricating oils by Ferriset al., Ind. and Eng. Chemistry, vol. 23, page 753, July 1931. In linewith the comparison made in this article, 'the graphs as hereinpresented, show, in general, the halogenated solvents to be superior tothe corresponding non-halogenated solvents for the selective separationof a hydrocarbon oil into fractions respectively more parafilnic andmore naphthenic.

Furthermore, I have found that the positio of the halogen atom in thesubstituted aromatic compound, i. e., the ortho, meta or para positionwith regard to the substituent group, appears to be a factor of minorimportance in the selective solvent action of the compound. Reference toTable II, given below, shows that neither the position nor the kind ofhalogen present in the aromatic compound exerts-any marked iniiuencecurve represents the results obtained by extracupon selectivity.

Table II Ratio vol. Visgrav. Vis-grav. solvent ggfiog? cl'af lfCglgfggitsff dis' cggggggf sock oil stock solved o1l Solved o oil oilOehler aniline a o. sa 62. o o. 81o as. o o. 875 [Minor-anilla@ a o. sass1. s o. 811 as. 5 o. 871 p-chlor-aniline 3 o. Bao 60. o o. sro 40. o o.37o o-brom aniline 3 0. 836 63. 3 0. 810 36. 7 0. S80

tion with the corresponding halogenated solvent. Since the primaryobject of the extraction process is the production of the greatest quan-F'rom the foregoing data it will be seen that by extraction of a mineraloil with a halogenated aromatic compound there may be obtained oilfractions which are ,respectively more paramnic and more naphthenic thanthe original oil. By repetition of the extraction process or by acontinuous countercurrent process, the undlssolved oil fraction may berendered increasingly paraillnic, as evidenced by a progressivelydecreasing viscosity-gravity constant.

In extracting oils containing appreciable quantities of wax, such oilsmay be dewaxed, for example, by cold settling or centrifuging prior tocarrying out the extraction. My process is operable, however, in theabsence of preliminary de- Waxing.

For brevity, in the appended claims the term fliquid polysubstitutedbenzene containing as nuclear substituents at least one halogen from thegroup consisting of chlorine and bromine and at least one substituentother than halogen and alkyl is employed in a generic sense to includeone or a mixture of two or more polysubstituted benzenes in whichnuclear hydrogen atoms are replaced by at least one atom of a halogenfrom the group consisting of chlorine and bromine and at least onesubstituent other than halogen and alkyl, said compounds having meltingpoints of less than substantially 200? C., and` being liquid at thetemperature and under the operating conditions of the extractionoperation; or a mixture of solvents containing substantial amounts of fsaid polysubstituted benzenes. The term viscous oil" is to be understoodas comprehending an oil of substantial viscosity, i. e., of the order of50 seconds Saybolt universal at 100 F., or more.

What I claim is:

1. In the art of refining mineral oils, the process which comprisesseparating an oil containing parailnic and naphthenic hydrocarbons intofractions respectively richer in parainic and naphthenic compounds byextracting said oil with a liquid polysubstituted benzene containing asnuclear substituents at least one halogen from the group consisting ofchlorine and bromine and at least one substituent other than halogen andalkyl.

2. In the art of refining mineral oils, the process which comprisesadding a liquid polysubstituted benzene containing as nuclearsubstituents at least one halogen from the group consisting of chlorineand bromine and at least one substituent other than halogen and alkyl toan oil containing paraiinic and naphthenic hydrocarbons, heating themixture to such temperature as to effect solution, cooling the solutionto form a two-layer system, and separating the upper layer from thelower layer.

3. In the art of rening mineral oils, the process which comprises addinga liquid polysubstituted benzene containing as nuclear substituents atleast one halogen from the group consisting of chlorine and bromine andat least one substituent other than halogen and alkyl to an oilcontaining paranic and naphthenic hydrocarbons, heating the mixture tosuch temperature as to eiect solution, cooling the solution to form atwo layer system, removing the lower layer, and similarly retreating theupper layer with a liquid polysubstituted benzene containing as nuclearsubstituents at least one halogen from the group consisting of chlorineand bromine and at least one substituent other than halogen and alkyl.

4. In the art of refining mineral oils, the process which comprisesbringing a mineral oil con` taining paraihnic and naphthenichydrocarbons into contact with a liquid polysubstituted benzenecontaining as nuclear substituents at least one halogen from the groupconsisting of chlorine and bromine and at least one substituent otherthan halogen and alkyl thereby to eflect solution of a portion richer innaphthenic hydrocarbons in the polysubstituted benzene, separating thesolution so formed from the remainder of the oil, and removing thesolvent from both portions oi the oil, thereby to obtain fractions ofthe oil respectively richer in parailinic and naphthenic hydrocarbons.

5. The process of treating a viscous fraction of a crude oil of one typecontaining parafnic and naphthenic hydrocarbons to procure a fractionhaving the quality of a corresponding fraction of a crude oil ofdifferent type having a greater content of parainic hydrocarbons, whichcomprises extracting the viscous fraction with a liquid polysubstitutedbenzene containing as nuclear substituents at least one halogen from thegroup consisting of chlorine and bromine and at least one substituentother than halogen and alkyl, and separating the oil so treated intoportions respectively richer in parafnic and naphthenic hydrocarbons.

6. In the art of rening mineral oils, the process which comprisesbringing a liquid polysubstituted benzene containing as nuclearsubstituents at least one halogen from the group consisting of chlorineand bromine and at least one substituent other than halogen and alkylinto intimate contact with a viscous hydrocarbon oil of a quality otherthan that of a Pennsylvania type viscous oil, and containing parafiinicand naphthenic components, thereby to dissolve from the oil substantialamounts of its naphthenic components, thereafter removing the solventand oil dissolved therein from that portion of the oil which remainsundissolved, thereby to produce an oil such as is normally obtained fromPennsylvania type crude by distillation.

'7. In the art of rening mineral oils, the process which comprisesbringing a mineral oil containing parafnic and naphthenic hydrocarbonsinto contact with a liquid polysubstituted benzene containing as nuclearsubstituents at least one halogen from the group consisting of chlorineand bromine and at least one substituent other than halogen and alkylthereby to effect solution of a portion 4richer in napthenichydrocarbons in the solvent, separating the solution so formed from theVremainder of the oil, and retreating the oil remaining with additionalamounts of a liquid polysubstituted benzene containing as nuclearsubstituents at least one halogen from the group consisting of chlorineand bromine and at least one substituent other than halogen and alkyl.

8. 'I'he process for separating mineral oils containing paraiiinic andnaphthenic hydrocarbons' into fractions which comprises bringing the oilinto Contact with a liquid polysubstituted benzene containing as nuclearsubstituents at least one halogen from the group consisting of chlorineand bromine and at least one substituent other than halogen or alkyl,thereby to eiTect solution of a portion of the oil richer in naphthenichydrocarbons in the said polysubstituted benzene, separating thesolution so formed from the remainder of the oil, and distilling thesolvent from both of the portions of the oil, thereby t/o obtainfractions of the oil respectively richer in paraflinic and naphthenichydrocarbons.

9. The method of producing parafinic lubricating oil from mixed basecrude which comprises distilling the crude and bringing a portionthereof into contact with a liquid polysubstituted benzene containing asnuclear substituents at least one halogen from the group consisting ofchlorine and bromine and at least one substituent other than halogen'oralkyl, thereby partially dissolving the oil, separating' the saidpolysubstituted benzene solution of oil so treated, and removing thepolysubstituted benzene from the treated oil.

10. In the art of reiining mineral lubricating oil containing parafnicand naphthenic hydrocarbons, the step of fractionally extracting the oilwith a liquid polysubstituted benzene containing as nuclear substituentsat least one halogen from the group consisting of chlorine and bromineand at least onesubstituent other than halogen or alkyl, to eiect aseparation of fractions respectively richer in parafnic and naphtheniccompounds.

11. The process of treating a viscous fraction of a crude oil of onetype containingA parainic and naphthenic hydrocarbons to procure afraction having the quality of a corresponding fraction of a crude oilof diierent type having a greater/content of paraflinic hydrocarbons,which comprises extracting the viscous fraction with a liquidpolysubstituted benzene containing as nuclear substituents at least onehalogen from the group consisting of chlorine and bromine and at leastone substituent other than halogen or alkyl, and separating the oil sotreated into portions respectively richer in parafiinic and naphthenichydrocarbons. I

12. The process of treating a viscous fraction of a mixed base crude oilto procure a fraction having the quality of a corresponding fraction ofa parailnic base crude, which comprises extracting the viscous fractionwith a liquid polysubstituted benzene containing as nuclear substituentsat least one halogen from the group consisting of chlorine and bromineand at least one substituentother than halogen or alkyl, and separatingthe oil so treated into portions respectively richer in paraffinic andnaphthenic compounds.

13. In the art of refining mineral oils, the process which comprisesbringing a mineral oil containing'parafiinic and naphthenic hydrocarbonsinto contact with a liquid polysubstituted benzene containing as nuclearsubstituents at least one chlorine atom and at least one of the groupcomprising the hydroxyl, nitro, aldehyde, amino and substituted aminogroups, thereby to effect solution of a portion richer in naphthenichydrocarbons in the solvent, separating the solution so formed from theremainder of the oil, and removing the solvent from both portions of theoil, thereby to obtain fractions of the oil respectively richer inparaffinic and naphthenic hydrocarbons.

14. In the art of rening mineral oils, the p ess which comprises addinga liquid polysu stituted benzene containing as nuclear substituents atleast one chlorine atom and at least one of the group comprising thehydroxyl, nitro, aldehyde, amino and substituted amino groups, to aviscous oil liquid at ordinary temperatures containing paraiinic andnaphthenic hydrocarbons, lheating the mixture to a temperaturesuiiicient to eiect solution, cooling the solution to a temperaturesufficient to form two layers respectively richer in naphthenichydrocarbons and paraiiinic hydrocarbons other than wax, and separatingthe upper layer richerl in paraflinic hydrocarbons from the lower layerricher in naphthenic hydrocarbons.

15. In the art of rening mineral oils, the process which comprisesbringing a liquid polysubstituted benzene containing as nuclearsubstituents at least one chlorine atom and at least one of the groupcomprising the hydroxyl, nitro, aldehyde, amino and substituted aminogroups, into intimate contact with a viscous hydrocarbon oil of aquality other than that of a Pennsylvania type viscous oil, andcontaining paraflinic and `naphthenic components, thereby to dissolvefrom the oil substantial amounts of its naphthenic components,thereafter removing the solvent and oil dissolved therein from thatportion of the oil which remains undissolved, thereby toproduce an oilsuch as is normally obtained from Pennsylvania typ'e crude bydistillation.

16. 'Ihe process of decreasing the viscositygravity constant of aviscous mineral oil which comprises extracting the oil with a liquidpolysubstituted benzene containing as nuclear sub'- stituents at leastone halogen from the group consisting of chlorine and bromine and atleast one substituent other than halogen and alkyl.

17. The process of decreasing the viscositygravity constant of a viscousmineral oil at least 0.015 which comprises extracting the oil with aliquid polysubstituted benzene containing as nuclear substituents atleast one chlorine atom and at least one of the group comprising thehydroxyl, nitro, aldehyde, amino and substituted amino groups. l

18. The process of treating a viscous mineral oil of viscosity-gravityconstant between substantially 0.808 and 0.875 to reduce theviscositygravity constant by at least 0.0.15, which comprisesfractionally extracting said viscous oil with a liquid polysubstitutedbenzene containing as nuclear substituents at least one halogen and atleast one of the group comprising the hydroxyl, nitro, aldehyde, aminoand substituted amino groups.

19. The process of treating a viscous mineral oil of viscosity-gravityconstant between substantially 0.808 and 0.836 to reduce theviscositygravity constant by at least 0.015, which comprisesfractionally extracting said viscous oil with a liquid polysubstitutedbenzene containingr as nuclear substituents at least one halogen and atleast one of the group comprising the hydroxyl, nitro, aldehyde, 'aminoand substituted amino groups.

20. The process oiA treating a viscous mineral oil of viscosity-gravityconstant higher than 0.835 to produce an oil having a viscosity-gravityconstant of less than 0.828 which comprises fractionally extracting saidviscous oil with a liquid polysubstituted benzene containing as nuclearsubstituents at least one halogen and at least one of the groupcomprising the hydroxyl, nitro, aldehyde, amino and substituted aminogroups.

21. In the art of 4refining mineral oils, the process which comprisesseparating an oil containing paralnic' and naphthenic hydrocarbons intofractions respectively richer in parainic and naphthenic compounds byextracting said oil with a polysubstituted benzene containing as nuclearsubstituents chlorine and an amino group.

22. In the art of refining mineral oils, the process which comprisesseparating an cil containing paralinic and naphthenic hydrocarbonsprocess which comprises separating an oil containing parafllnic andnaphthenic hydrocarbons into fractions respectively richer in parafilnicand naphthenic compounds by extracting said oil with a polysubstitutedbenzene containing as nuclear substituents chlorine and a nitro group.

24. A process for separating mineral oil containing parailinic andnon-paramnic fractions into more parafiinic and less paraflinicfractions which comprises commingling said oil with chloraniline tocause phase separation and separating the chloraniline and dissolvedfractions from the remaining undissolved more paraihnic fractions.

25. A process for separating oil into fractions which comprisescommingling said oil with chloraniline to cause separation of raffinateand extract phases, separating the extract phase containing chloranilineand oil fractions dissolved thereinfrom the raifmate phase containingthe undissolved fractions, and separating the chloraniline from saidfractions.

26. A process for the separation of oil into fractions which comprisescommingling said oil with chloraniline below the temperature of completemiscibility to cause separation of extract and rainate phases, andseparating the extract phase containing chloraniline and oil fractionsdissolved therein from the ramnate phase containing the undissolvedfractions.

27. In a process of treating liquid hydrocarbon mixtures containing bothsaturated and unsaturated constituents, the steps of extracting the oilwith a solvent comprising monochlorophenol as a selective solvent toform a rafilnate' phase and an extract phase, and separating saidphases.

28. A process for separating mineral oil containing paraflinic andnon-paraiiinic fractions into more parainic and less paraiiinicfractions which comprises commingling said oil with chloro nitrobenzeneto cause phase separation and separating the chloro nitrobenzene anddissolved fractions from the remaining undissolved more paraiiinicfractions.

29. A process for separating oil into fractions Which comprisescommingling said oil with chloro nitrobenzene to cause separation ofrailinate and extract phases, separating the extract phase containingchloro nitrobenzene and oil fractions dissolved therein from the rainatephase containing the undissolved fractions, and separating the chloronitrobenzene from said fractions.

30. A process for the separation of oil into fractions which comprisescommingling said oil with chloro nitrobenzene below the temperature ofcomplete miscibility to cause separation of extract and raiiinatephases, and separating the extract phase containing chloro nitrobenzeneand oil fractions dissolved therein from the raflinate phase containingthe undissolved fractions.

31. In a process of treating liquid hydrocarbon mixtures containing bothsaturated and unsaturated constituents, the steps of extracting the oilwith a solvent comprising chloro nitrobenzene as a selective solvent toform a raiinate phase and an extract phase, and separating said phases.

SEYMOUR W. FERRIS.

